This invention relates to energy conversion apparatus and is primarily concerned with energy conversion apparatus operable by a flow of fluid.
The economic viability of any wind energy conversion project is, in common with any other prime source energy conversion project, determined by the ratio of, on the one hand, the capital costs involved in the construction of the wind energy conversion apparatus plus the costs incurred in its maintenance during the productive life thereof, and on the other the total energy produced by the apparatus during that period.
Conventionally, windmills of a wide range of differing forms are employed in wind energy conversion. One might think, at first, that a large windmill would be more cost effective than two smaller ones sweeping an equivalent area. In practice this turns out to be true only up to a certain point, a point determined by other factors notably wind behaviour.
The rate of energy conversion by a windmill is a function of the area swept out by the blades of the windmill; but the dynamics of the windmill is a function of the blade mass, that is to say the cube of the blade dimensions. So the rotor mass increases disproportionately with size to the energy produced. This translates to disproportionately higher costs to cope with the dynamic loads generated.
It is an object of the present invention to provide wind energy conversion apparatus which may avoid the problems and, hence, the economic limitations of the windmill, as mentioned above, but more generally to provide a novel form of energy conversion apparatus operable by flow of a fluid with respect thereto.